Our earlier British patent specification GB-A-No. 1,381,871 describes and claims a machine for closing filled bags by applying an adhesive tape tie to the gathered together open end of such a bag. The machine described in this earlier specification includes a stop movable between a retracted position and an advanced position in which it extends into the path of the open end part of the bag and against which the end part of the bag is compressed to gather it together. The stop then moves to its retracted position together with the compressed end part of the bag and in so doing transfers the compressed and gathered together end part of the bag into contact with the adhesive tape used to form the tie. The machine also includes clamping means to clamp the adhesive tape around the gathered together neck of the bag and subsequently release the closed end part of the bag to allow it to be moved out of the guide. The clamping means disclosed in our earlier specification includes a pair of spring-loaded jaws which in one example move forwards and backwards in the direction of movement of the gathered together end part of the bag and in the other example are fixed downstream from the adhesive tape in the direction of movement of the bag.
Our British patent specification GB-A-No. 1,517,031 which is a patent of addition to the earlier specification also describes a bag tying machine but in the example described in this specification the stop is omitted and the end of the bag is gathered together against the adhesive tape which is supported directly by the clamping means. This arrangement is, in general, successful in operation but the adhesive tape may not be sufficiently supported by the clamping means to prevent it being distorted as the end of the bag is gathered together against it. When the adhesive tape is distorted in this way, the adhesive tape tie is incorrectly formed.